Quarterly Estimated Tax Calculator
Find your penalty-safe 2026 quarterly payment using IRS safe harbor rules — with all four due dates
Revenue minus business expenses (Schedule C)
Day-job income alongside your business
Counts toward your estimated payments
Form 1040, line 24 — leave 0 if unknown
Estimate only: Uses 2026 federal tax law — standard deduction, brackets, SE tax with the $184,500 Social Security wage base, and the 20% QBI deduction. State estimated taxes are separate. Not tax advice — verify with IRS Form 1040-ES or a professional.
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Quick summary
Enter your expected self-employment profit (plus any W-2 income and withholding) to get a penalty-safe quarterly payment. The IRS safe harbor means no underpayment penalty if you pay the smaller of 90% of this year's tax or 100% of last year's (110% if your prior AGI topped $150,000). 2026 due dates: April 15, June 15, September 15, and January 15, 2027.
Reviewed by Simple Calculators TeamLast reviewed
How to use this calculator
- Enter the inputs requested by the calculator.
- Choose the units or options that match your situation and review the assumptions.
- Run or update the calculation to see the result.
- Review the result, breakdown, and formulas shown on the page.
- Check the inputs, units, dates, and limitations before saving or sharing the result.
Frequently asked questions
Who has to pay quarterly estimated taxes?
Generally anyone who expects to owe $1,000 or more when filing and whose withholding won't cover the safe harbor — freelancers, contractors, landlords, and W-2 employees with significant side income. If a day job withholds enough to hit the safe harbor, no quarterly payments are needed.
What is the safe harbor rule?
You avoid the underpayment penalty if your combined withholding and estimated payments reach the smaller of: 90% of this year's total tax, or 100% of last year's total tax (110% if last year's AGI exceeded $150,000). Paying based on last year's number is popular because it's a known, fixed target.
When are 2026 quarterly taxes due?
April 15, 2026 (Q1), June 15, 2026 (Q2 — only two months after Q1), September 15, 2026 (Q3), and January 15, 2027 (Q4). If a date falls on a weekend or holiday it shifts to the next business day.
What happens if I skip a quarterly payment?
The IRS charges an underpayment penalty that works like interest (currently based on the federal short-term rate plus 3%) on the shortfall for each quarter, even if you pay everything at filing. The penalty is computed per quarter, so catching up later doesn't fully erase it.
How do I actually pay?
Pay online at IRS Direct Pay or your IRS Online Account (free bank transfer), by card via approved processors (fee), or by mailing Form 1040-ES vouchers. Most states have a parallel estimated tax system — this calculator covers federal only.
Key terms
- Safe Harbor
- Payment thresholds (90% current year / 100–110% prior year) that protect you from underpayment penalties regardless of what you finally owe.
- Form 1040-ES
- The IRS worksheet and payment vouchers for calculating and paying quarterly estimated taxes.
- Self-Employment Tax
- 15.3% (12.4% Social Security capped at $184,500 in 2026 + 2.9% Medicare) on 92.35% of net self-employment profit.
- Underpayment Penalty
- An interest-style charge on each quarter's shortfall below the safe harbor, assessed even if you pay in full at filing.
Methodology, sources & limitations
This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.
For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.
Quarterly Estimated Taxes: The Freelancer's Complete Guide
Nobody withholds taxes from self-employment income — the IRS expects you to send it yourself, four times a year, and charges interest-like penalties per quarter if you don't. Here's the full system: who owes, how much, when, and the mistakes that cost real money.
Do you actually need to pay quarterly?
The test: will you owe $1,000 or more at filing after subtracting withholding and credits? For pure freelancers, that threshold arrives around $6,000–7,000 of annual net profit. If you also have a W-2 job, you may escape entirely — withholding counts toward the safe harbor, and raising it (via a W-4 adjustment) is often simpler than making separate payments. Withholding has a superpower: the IRS treats it as paid evenly through the year no matter when it happens, so a December withholding bump can retroactively fix an underpaid year. Estimated payments can't do that.
A complete first-year example: $80,000 of net profit
Take a single freelancer expecting $80,000 net profit (after expenses) in 2026, with no W-2 income. Self-employment tax applies to 92.35% of profit ($73,880): 12.4% Social Security plus 2.9% Medicare on that base is $11,304. Half of it ($5,652) is deductible.
The QBI deduction takes 20% of qualified income ($74,348 × 20% = $14,870). Taxable income: $80,000 − $5,652 − $14,870 − $16,100 standard deduction = $43,379. Federal income tax on that: $4,957. Total tax: about $16,261 — an effective rate of 20.3% on the $80,000.
The penalty-safe payment under the 90% rule: $14,635 for the year, or $3,659 per quarter. Note this leaves about $1,600 due at filing — pay $4,065/quarter instead to cover everything. These are exactly the numbers the calculator above produces with its default inputs.
Safe harbor: your insurance against penalties
The prior-year harbor is the freelancer's best friend in a growth year: if last year's tax was $12,000, paying $3,000/quarter makes you penalty-proof even if this year's income doubles. You'll owe the balance in April, but penalty-free — and you've had use of the money all year.
| Rule | You must pay | Best when |
|---|---|---|
| 90% of current year | 90% of this year's total tax | Income dropped from last year |
| 100% of prior year | Last year's total tax (line 24) | Income is rising — lock in the smaller known number |
| 110% of prior year | 1.1× last year's tax | Required instead of 100% when prior-year AGI exceeded $150,000 |
The 2026 payment calendar
Pay free by bank transfer at IRS Direct Pay or through an IRS Online Account (which also shows your payment history — invaluable at filing time). Mark the payment as “Estimated Tax — Form 1040-ES” for the correct year.
| Quarter | Income period | Due date |
|---|---|---|
| Q1 | Jan 1 – Mar 31 | April 15, 2026 |
| Q2 | Apr 1 – May 31 | June 15, 2026 |
| Q3 | Jun 1 – Aug 31 | September 15, 2026 |
| Q4 | Sep 1 – Dec 31 | January 15, 2027 |
The five expensive mistakes
- Missing the June 15 date because you assumed quarterly meant every three months. Q2 is two months after Q1.
- Forgetting state estimated taxes — most states with income tax run a parallel system with similar dates and their own penalties.
- Paying on gross revenue instead of net profit. Track expenses all year; every legitimate deduction saves both income tax and 15.3% SE tax.
- Not saving as you earn. Move 25–30% of every payment into a separate tax account the day it arrives — the math above shows why (20.3% federal effective at $80k, plus state).
- Skipping a bad quarter entirely. If income fluctuates, pay what the quarter's actual income justifies (Form 2210's annualized method exists for this) — zero payments accrue penalties even if you catch up later.